Stylistic Changes

Neatened everything up.

- Added text shadows on the top nav at 0.3 opacity for legibility.
- Added .published, .draft and .archive selectors for legibility when checking to see if posts are published etc.
- Fixed alignment on empty posts, pages and comments so they're center aligned, also placed them in a div rather than a <p> element.
- Tidied up Site Metadata, added padding and right-aligned the text for continuity.